Root crops, which are generally capable of efficient production of calories under marginal soil conditions, account for over 50 percent of Africa's total staples on a volume base. A wide variety of root and tuber crops is grown - some, such as potato, are exotic and need good conditions for an acceptable yield. These crops are restricted to specific locations such as the highlands of Rwanda and Burundi. Others such as cassava perform and yield well under harsh conditions, having high tolerance to stresses such as drought. Their long harvesting period is an asset, providing a natural 'storage' environment.

Pests and diseases cause production losses of root crops of over 50 percent. Average yields of cassava, potato and yam are 8-10 tonnes per hectare in Africa. With improved technologies, yield can be 5-10 times this average (Nyiiara, 1994: 50-55). The yield gap has not narrowed in the last decade due to lack of resources to invest in the soil to improve its fertility and the absence of supplementary irrigation to lower risks due to drought. Moreover, various diseases and pest cause considerable depression in actual yields.

In addition, attempts by farmers to market cassava products have fallen well short of their potential. Because it is highly perishable and contains toxic components, cassava needs special attention during post-harvest storage and processing. Processed products, and the enhanced importance of root and tuber crops as feed in the expanding meat production sector outside Africa, promise further development opportunities (Bruinsma, 1996).

<< Previous - [Page 54 of 171] - Next >>